Process tube



FIG. 1 is a perspective view of a process tube;

FIG. 2 is a side plan view of the process tube;

FIG. 3 is an end plan view of the process tube;

FIG. 4 is a top plan view of the process tube;

FIG. 5 is a bottom plan view of the process tube; and,

FIG. 6 is a cross-sectional view of the process tube taken along line 6in FIG. 4.

The broken lines immediately adjacent the shaded areas represent thebounds of the claim, and other broken lines illustrate portions of theprocess tube that form no part of the claimed design. None of the brokenlines form a part of the claimed design.

CLAIM The ornamental design for a process tube, substantially as shownand described.